Additive for motor fuels



Patented July 26, 1949 STATES PATENT OFFICE ADDITIVE FOR MOTOR/FUELS John L. Volz, Los Angeles, and Karl J. Korpi, Pasadena. Calif., assignors to Union Oil Commany of California, Los Angeles, Callf a corporation of California No Drawing. Application December 4, 1944,

Serial No. 586,649

8 Claims. 1

- This invention relates to motor fuels and particularly to the addition of certain materialsto motor'fuels which contain an anti-knock agent and organic sulfur compounds. This is a continuation-impart of our copending application Ser. No. 355,822 (now abandoned).

It-is known that the addition of certain antifler will offset the detrimental effect of the sulfur compounds in lowering the knock rating improvement otherwise imparted by the tetra ethyl lead or other anti-knock material.

' According to the present invention internal combustion engines which employ fuels containing an anti-knock agent together with organic sulfur compounds in an amount sufficient to have a detrimental effect on the anti-knock imparting properties of the anti-knock agent are operated more efficiently by adding to the fuels which are so used, small amounts of the additives described herein. It appears that sulfur-bearing gasolines containing tetra ethyl lead are favorably modified by the addition of very small percentages of these additives, which are oil-soluble compounds with metal constituents having stronger afiinity for the sulfur present in the gasoline than the lead inthe tertra ethyl lead has for said sulfur. Similar fuels containing other anti-knock agents are also beneiitted.

' The additives of this invention consist of esters of the non-gaseous elements of group 5B of the 40 periodic system, namely phosphorus, arsenic, anti mony" and bismuth, of which the compounds of arsenic and-antimony are referred. Compounds which are especially useful are the esters of the 2 ethyl ether of diethylene glycol arsenite. The resulting product was similarly used and tested. and was found to have an octane number of 81.

The arsenite of the above example was prepared by heating about four mols of the monoethyl ether of diethylene glycol and one mol of arsenious oxide in a still until one mol of water was removed by distillation. The water removed by distillation was formed during the reaction between the alcohol and the arsenious oxide, which probably took place as follows:

When all of the water was distilled, all of the,

arsenious oxide had disappeared from the still. This occurred at a temperature of approximately 280 F.

The product formed in the above case was presumably the dimono-ethyl ether of diethylene glycol arsenite indicated, which contains approximately 28% AS203, and probably contained some water of hydration. When this dimono-ethyl ether of diethylene glycol arsenite was further distilled, it was observed that the material first obtained was mono-ethyl ether of diethylene glycol. As a second product of the distillation, a monomono-ethyl ether of diethylene glycol arsenite presumably of formula [(C2H5)O(C2II4)O(C2H4)O]ASO was obtained at a temperature of about 540 F.

, This product was also effective in the process of this invention. The theoretical arsenious oxide content of this monomono-ethyl ether of diethylene glycol arsenite is approximately 44%. The actual arsenious oxide contents of the di= and mono-derivatives just described were about and respectively, by analysis.

The above additives are illustrative of the preferred additives of this invention, which are preabove elements prepared by reacting the oxides 45 of the above elements in their trivalent states, with an alcohol of the polyglycol ether type.

- As a specific example of the invention a cracked gasoline having a boiling range of about 100 F.

to about 386 F. and containing about 0.51% sulfur and 3 ml. of tetra ethyl lead fluid per gallon was Prepared and used in an internal combustion engine. It was found to have 'an octane number by the-A. S. T. M. motor method of '17.

pared by reacting an oxide of trivalent arsenic, antimony, bismuth, or phosphorus with a polyglycol ether having the general formula m and n are integers, m preferably being 2,-

though it may also be between 1 and 5 or higher, and n preferably being 2 although it may be 3 or higher. For the above mono-ethyl ether of diethylene glycol R is ethyl and m and n are each 2. Other familiar polyglycol ethers which may To thisgasoline was added about 0.5% of monoalso be employed are the mono-ethyl ether of diethylene glycol, the mono-butyl ether of diethylene glycol, and di-ethylene glycol, in which R is methyl, butyl, and hydrogen, respectively, and m and n are each 2. These may be reacted with the trivalent oxides of all of the above non-gaseous elements of group 53, without the use of a catalyst, as in the above example. So also may triethylene glycol and its mono-alkyl ethers of the above formula, in which m=2 and 11:3, and other less well-known compounds in which m=1, 3 or other low integer, and n=2 or a higher integer, and R is hydrogen or an alkyl group as above. It may be observed that it is preferable in the above non-catalytic reaction to add a small amount of water to the reaction mixture prior to the heating operation, since this appears to reduce the vigor of the reaction and make the operation smoother.

Although the above polyglycol ethers are preferred for the preparation of the additives of this invention, other alcohols of the above general formula may also be employed in which n is less than 2, but in this case the reaction requires a catalyst. Those alcohols in which n is 1 or higher may be termed glycol ethers. Familiar examples of alcohols of the above general formula in which n=1 are ethylene glycol, the ethyl ether of ethylene glycol, the methyl ether of ethylene glycol, the butyl ether of ethylene glycol and the like. In these latter examples, m in the above general formula is 2 and R is hydrogen, ethyl, methyl, and butyl respectively. Other homologs in which R is another alkyl group may also be used. Although ethylene glycol and the methyl ether of ethylene glycol will react to some extent with the oxides of the non-gaseous elements of group 53 in the absence of a catalyst, the higher ethers of this type are relatively unreactive, and the reaction is preferably carried out in the presence of a catalyst with all of these materials. Suitable catalysts are esterification catalysts such as strong acids including hydrochloric, hydrobromic, sulfuric, phosphoric, sulfonlc acids and the like, the inorganic acids, especially hydrochloric, being preferred.

As an example of the above reaction, 4 mols of the methyl ether of ethylene glycol may be heated with one mol of arsenious oxide and suflicient concentrated hydrochloric acid to provide three mols of water. The mixture is refluxed, and the water present and-that formed in the reaction is allowed to escape. Substantially all of the arsenious oxide reacts within a few hours, and the resulting product contains about 42.5% of arsenious oxide by analysis, corresponding to the theoretical value for the di-methyl ether of ethylene glycol arsenite. The other alcohols of this type will also react, as will the other oxides of trivalent Sb, Bi, and P. The products are useful additives of this invention.

It has been found that simple alcohols, which have the above general formula in which 12:0, may also be reacted with the above oxides to produce additives of this invention. Examples of the simple alcohols are ethyl alcohol, butyl alcohol, amyl alcohol and the like. All of these materials require the use of an esterlflcation catalyst such as described above.

As an example of the preparation of an additive of this invention from a simple alcohol, four mols of amyl alcohol, one mol of arsenious oxide and sufiicient 31% hydrochloric acid to provide three mols of water were heated together in a still. During the operation, the distillate recovered consisted of two phases, i. e. an aqueous phase containing hydrochloric acid and an alcohol phase. As the distillation progressed, the alcohol removed during the distillation was returned to the still. When no more water was observed in the distillate and all of the solid arsenious oxide had disappeared from the still, the reaction was considered complete. Di-amyl arsenite was thus produced containing the theoretical percentage of approximately 37% of arsenious oxide.

The procedure employed in the manufacture of amyl arsenite was followed in a case of producing octyl arsenite. In this case, dioctyl arsenite was produced containing the theoretical percentage of approximately 29% of arsenious oxide.

The above additives .are useful in gasolines (which generally boil below about 400 P.) which contain tetra ethyl lead or other alkyl lead compound such as methyl triethyl lead and the other analogous lead-alkyl compounds and other antiknock metal-organic compounds, when these compounds are employed in gasolines which contain a suflicient amount of organic sulfur compounds to have a retarding effect on the antiknock imparting properties of the anti-knock agent. Sulfur compounds which are particularly detrimental are the alkyl sulfides and thiophanes and mercaptans found in crude oil and petroleum distillates, and the disulfldes, trisulfides and other polysulfides formed by treaatment of such mercaptan-containing distillates to sweeten them. The thiophenes found in cracked gasolines are also somewhat detrimental. These sulfur compounds are particularly detrimental when present in quantities greataer than about 0.1% sulfur by weight.

In practicing the invention, small percentages, preferably less than about one-half per cent, of the oil-soluble esters of this invention are added to the sulfur-bearing gasoline containing an anti-knock agent as described above. Ordinarily, the amount of additive employed would be in the order of about 0.1%, and commercially between about 0.01% and 0.1%. Larger amounts up to about may be employed within the scope of the invention, or even greater amounts if necessary. The gasoline so treated is then employed as a fuel in an internal combustion engine, and is found to result in improved performance. The additives may also be injected into the fuel before or after carburetion, if desired, or blended with the anti-knock agent, and the blend injected into the fuel before or after carburetion, or incorporated into the fuel in any other manner desired.

In the preparation of the additives of this invention other compounds of the non-gaseous elements of group 53 may be reacted with the alcohols. For example the acids of these elements such as arsenious acid and the like may be employed. Other modifications of this invention which would occur to one skilled in the art are to be considered a part of the invention as defined in the following claims.

We claim:

1. A motor fuel according to claim 2 in which the alcohol is a glycol ether.

2. A hydrocarbon gasoline motor'fuel' containing a lead alkyl anti-knock-agent and organic sulfur compounds in an amount sufficient to have a retarding effect upon the anti-knock-imparting properties of the anti-knock agent, together ing properties of the anti-knock agent, together with an arsenite of an alcohol having the general formula R OCmH2mMOH in which m is-an integer between lands and "is i. an integer between 0. and 3 and R is selectedfrom the-class consisting of hydrogen" and alkyl groups-in an amount between about 0.01% and 0.5% by weight. .3.-A gasoline motor fuel containinga lead alkyl anti-knock agent and organic sulfur compounds in an amount suflicient to have a retarding effect upon the anti-knock-imparting properties of the anti-knock agent, together with an arsenite of a mono-alkyl polyglycol'ether, in an amount between about 0.01% and 0.5% by weight. I

4. A hydrocarbon gasoline motor fuel containing alead alkyl' anti-knock agent and sulfur in; 1

an amount sufllcient to have aretarding effect uponthe anti-knock imparting properties of the anti-knock agent, together with diethylene glycol monoethyl ether arsenite, in an amount between about 0.01% and 0.5% by weight.

5. Amotor fuel according to claim 2 in which 20 the alcohol is a simple alcohol. inwhich 1: equals 0.

the alcohol is amyl alcohol.

7. A 'motor fuel according to claim 2 in which the alcohol is the methyl ether of ethylene glycol. A motor fuel according to claim 2 in which the amount of the arsenite is less than 0.1%.

A motor fuel according 2 which JOHN L. VOLZ. KARL J. KORPI.

3mm crrnp The following references are-ofrecord in the flleofthispatent: A UNITED sums PATENTS 2,405,560. Campbell Aug. 13, 1946 

